We are able to manage, design, develop, and source large fenestration projects. This can be in either glass, windows, curtain wall, expanded metal, or of any other type or configuration. We have a very large constellation of factories that we work with, and a wide and diverse collection of engineers in our extensive talent pool.

When we talk about fenestration, we often refer to glazing or other solutions as part of architectural design and construction. This can be glass, and more often is, but it also includes custom metal designs, and architectural embellishments as well.

This is a very interesting product segment that we have been involved in. And it is not without it’s challenges. I’ll tell you what. It’s something that we have enjoyed through all the troubles, trials and twists and turns that any large construction-based project would encounter.

While fenestration is generally associated with the glass, and metal iron-work associated with a given construction project, our involvement has been far more interactive. We have been involved in the design and implementation of off-site assemblies associated with fenestration solutions, then have them shipped and installed quickly at the construction site.

Naturally, the savings on the construction and installation costs are offset by the care and due diligence at our fabrication factories. We absolutely need to have everything absolutely perfect before we ship the components out, and we also need to make sure that there are no problems in component transit.

Let’s start with reviewing what fenestration is…

What is Fenestration?

Fenestrations are basically the outside sheathing on a building façade. This can be glass, metal, wood, or any other material in any size or shape. In regular day to day usage, the term fenestration refers to “glass window” projects for buildings.

Most commonly, the windows for a large hotel, office building or similar structure is considered the fenestration requirements for that structure. Much like this…

And that would be that.

But…

We have also been involved in other kinds of projects. For instance, we have been involved in Curtain Wall operations for large office buildings. These are large sheets of glass that serve to protect the structure from the climate and weather, but are non-structural in utility.

• Glass components for buildings.
• Used to sheath the outside of the building from weather.
• Is aesthetically pleasing to the eye.

In general, we source all the components and make sure that they meet the requirements for the project. But it is more than that, you need to take extra care in shipping the stillages holding the glass to make sure that they would not be damaged in transit.

Ah. But, the over all effect is outstanding.

There are those that consider the fenestration of a building as a way to inject light into the interior of a structure, and yes that is one of it’s purposes. But it is more than that. It is the way that the building can be secure from the weather, the climate, and from the ravages of crime.

As we well know from all the damage from the riots of 2020, there is a need to have beautiful and functional fenestration solutions in urban areas that are prone to riots and aggravated protests.

But you know, if you think about it, fenestration can mean more than just a bunch or windows, no matter how they are made or their role in the structural integrity of the building. It can mean the outer appearance of a building that lets in light, but does not use glass.

Like perforated metal or expanded mesh.

And that is a classification that we are adding to this (otherwise standard narrative of what a fenestration solution is). Here we look at decorative sheeting and sheathing solutions for large buildings and associated structures.

Types of Fenestration’s

There are plenty of styles and designs to choose from. You can go from windows and openings to mesh and metal grid works. Here are some of the most impactful styles for windows along with their uses.

The building architect, of course, would already have a pretty clear vision of what the exterior of the building or structure would look like. However, it is certainly useful to know what options are available in the event that you have a problematic fenestration solution. And, believe it or not, these kinds of situations do come up, and are problematic.

I can say that all of these types of fenestration projects we have participated in. While you might see a ton load of shiny sky-scrapers downtown in the cities, our experience is that the associated curtain wall projects are not that common. Mostly our fenestration projects revolve around hotels, small businesses such as clubs, public buildings, and parking garages. Not what you would expect, eh?

1. Slit Windows

These are not a common fenestration solution. But they are dramatic.

These are one of the smallest openings or voids that serve as fenestration’s. They provide intake of direct as well as diffused light and create a light and shadow pattern play in the interiors. It’s a pretty impressive appearance. These slits may or may not have glass windows.

For instance this house is a windowless, slit house…

These are generally adopted to light up the passages, corridors and also along the façades of huge dead masses to break the monotony and create the necessary play of voids.

These kind and style of windows are very popular in the United States for prisons and jails. They are placed either horizontally or vertically in the targeted building.

2. Jalis or Perforated Windows

This is also a fenestration solution that isn’t all that common (today at least).

These are similar to slits. However, a patterned pre-cast or metal jalis, is often a very elaborate structure. We can see this in many of the older buildings that still exist.

Jalis style adornment is popular from the Middle East up through and into Russia.

They are often quite decorative, and beautiful. They serve as a transparent façade yet creates the required bifurcation between inside and the outside environment.

Contemporaneously, modern jalis work is often up to local artisans, and other traditional gentlemen who still retain the skills to create impressive jalis adornments. We can help and assist finding people who can layout the necessary art work, and others who can carve or fabricate the jalis structure for you.

One of the benefits in working with Smoking Lion is our ability locate skilled craftsmen who can create beautiful jalis adornments, at a fraction of the cost of what it would be in the West. If you have any interest in jalis adornments, please give us a call and we will discuss projects that might be of interest to you.

4. Traditional Glass Windows and Doors

Most people consider fenestration projects as the collective windows (and doors) for a singular construction or building project. Which is probably what you, the reader considers. When many people talk about fenestration projects, they think in terms of this. They think windows; window schedules, and doors. But, the truth is that it is much more than that.

There’s a misconception that when discussing fenestration on building projects that it simply refers to windows and doors. In fact it covers all glazed areas including windows, doors, wall panels, curtain walling, skylights, vents and louvres.

There are many choices when it comes to designing and specifying fenestration systems into buildings. 

Understanding the basic attributes of the available choices allows for better design and specification writing. Taking the time to understand the differences and similarities between fenestration systems will ultimately deliver the best product choice for energy efficiency, sustainability, durability, aesthetics and cost effectiveness.

-CPD 14 2019: Fenestration on buildings

Here is a screen shot of one of our fenestration projects. This one in particular is a large hotel located in the United States. Like all fenestration projects, the allocation for final vendor selection and the release of the drawings for a given build always seems to come at the last possible minute.

5. Curtain Wall

These are enormous projects that sheath an entire building in glass.

A curtain wall is defined as thin, usually aluminum-framed wall, containing in-fills of glass, metal panels, or thin stone. The framing is attached to the building structure and does not carry the floor or roof loads of the building. The wind and gravity loads of the curtain wall are transferred to the building structure, typically at the floor line. Aluminum framed wall systems date back to the 1930’s, and developed rapidly after World War II when the supply of aluminum became available for non-military use.

Curtain wall systems range from manufacturer’s standard catalog systems to specialized custom walls. Custom walls become cost competitive with standard systems as the wall area increases.

Curtain walls can be classified by their method of fabrication and installation into the following general categories: [1] stick systems and [2] unitized (also known as modular) systems.

• In the stick system, the curtain wall frame (mullions) and glass or opaque panels are installed and connected together piece by piece.
• In the unitized system, the curtain wall is composed of large units that are assembled and glazed in the factory, shipped to the site and erected on the building. We tend to work primarily with unitized curtain wall systems. Vertical and horizontal mullions of the modules mate together with the adjoining modules. Modules are generally constructed one story tall and one module wide but may incorporate multiple modules. Typical units are five to six feet wide.

In all cases we can help design, select and fabricate the components for a given curtain wall project. It is, after all, what we do.

4. Expanded Metal Mesh

Expanded metal mesh which can be used for exterior facade is a form of metal sheet perforated with various shaped openings. It can be made of a range of materials. These materials can include such things as carbon steel, aluminum metal, stainless steel metal, nickel metal. In my humble opinion, copper is the most beautiful.

The truth is, however, that aluminum expanded metal mesh is the most common. It has the benefit of lighter weight and better corrosion resistance. Not only that, but a big plus is it’s hardening process. For, after being expanded by machine, the expanded metal mesh becomes stronger, lighter, and more rigid. It can also be anodized into different finishes and colors.

It is a great product and as such, it is widely used in various kinds of buildings, office building, and shopping mall.

There are more than 300 types of expanded mesh that are available for architectural use.

Here is a project using Aluminum expanded metal facade mesh. This mesh material is formed from a piece of metal and creating different shaped holes in one step, such as diamond, hexagonal, square, etc.

5. Special Designs

Here I would like to tell the story of a very special fenestration project that we worked on for a building in the UK. This building was to have a RF barrier in all the windows so that internal radio signals would not escape the building.

What we did was place a beautiful copper mesh inside the glass inner-layer.

The copper mesh would effectively block the RF signals, and were connected to the mounting pinions of the glass edge. All of which was grounded to the building structure.

It was more expensive than just plain single layer glass with a PVD inner-layer, but boy was the effect impressive.

And when the sun would shine on it, the building would have the effect of endless gold rainbows that would shimmer as you moved.

Types of Glazing

There are many options for covering the voids formed for or by various fenestrations. The most commonly used method is glazing. Glazing is used as it mainly provides permeability for the light to enter and is also covered with a Protective Skin. The glazing used are mainly based on the impact of it on the environment. They maintain the thermal comfort along with the heat gain on site or inside the structure.

Let’s talk about the different types of panes. There are really only a few that are of consideration…

• Single Pane (usually used for storm windows).
• Double Pane.
• Triple Pane,
• Quadruple Pane.

Single pane windows are a traditional choice for home remodeling and new construction projects, especially those with tight budgets. Due to their lower cost, single pane windows are also a great choice for window replacement projects or for use in garages, tool sheds, and other non-heated outbuildings. From our point of view, we will make windows based on the needs of our customers, and many (due to cost considerations) prefer to have single pane windows.

We can provide these single pane windows, but we have found that most of our customers prefer the double and triple pane glass…

Double Pane

Double pane windows consist of two pieces of glass with air or gas between the two panes. If gas is used, it is usually argon. Manufacturers often place decorative grids between the two panes to make the window appear as if it has divided light panes. With grids between the glass the window is easier to clean both inside and outside.

2. Triple Pane

When you are considering to make windows, the multiple pane windows are most desirable from a “green energy” point of view. They provide the best mixture of energy efficiency for a given cost.

Due to architectural advancement and breakthroughs, the triple pane window is becoming more and more popular recently. Unlike the double pane windows, it has three sheets of window glass pane, separated by 2 separate layers of gas. This 2 layers of airtight gasses provides improved insulation than the double pain.

3. Quadruple Pane

The quadruple pane window is by far, the most advanced type of window pane right now. The insulation is made even better by combining 4 sheets of window pane glass with three spaces filled with gas that are airtight. It significantly raises the functionality and features of the other two type of panes mentioned above. It is better in all the pros and advantages of all the panes listed above with the con of being super heavy weight and needs a tougher, more durable window frame and sash. Not to mention the more expensive price!

Low E-glass

Low-e glass has a microscopically thin, transparent coating—it is much thinner than a human hair—that reflects long-wave infrared energy (or heat). Some low – e”s also reflect significant amounts of short-wave solar infrared energy to protect the interior spaces from the harmful rays.

There is mainly a thin coating which helps to reflect the particles and various wavelengths. This Low – e glass can be used double or triple glazed as per the requirement according to the surrounding climatic conditions.

This technique is the most effective for glazed buildings to maintain the thermal comfort as well as for huge glass curtain walls.

Strength

Architectural glass comes in three different strength categories.

• Annealed glass is the most commonly used architectural glass. Because it is not heat-treated and therefore not subject to distortion typically produced during glass tempering, it has good surface flatness. On the downside, annealed glass breaks into sharp, dangerous shards. Heat-strengthened and fully-tempered glass are heat-treated glass products, heated and quenched in such a way to create residual surface compression in the glass. The surface compression gives the glass generally higher resistance to breakage than annealed glass.
• Heat-strengthened glass has at least twice the strength and resistance to breakage from wind loads or thermal stresses as annealed glass. The necessary heat treatment generally results in some distortion compared to annealed glass. Like annealed glass, heat-strengthened glass can break into large shards.
• Fully-tempered glass provides at least four times the strength of annealed glass, which gives it superior resistance to glass breakage. Similar to heat-strengthened glass, the heat-treatment generally results in some distortion. If it breaks, fully-tempered glass breaks into many small fragments, which makes it suitable as safety glazing under certain conditions.

Laminated glass

Laminated glass consists of two or more panes of glass adhered together with a plastic interlayer. Because it can prevent the fall-out of dangerous glass shards following fracture, it is often used as safety glazing and as overhead glazing in skylights.

The plastic interlayer also provides protection from ultraviolet rays and attenuates vibration, which gives laminated glass good acoustical characteristics. Because laminated glass has good energy absorption characteristics, it is also a critical component of protective glazing, such as blast and bullet-resistant glazing assemblies.

Tempered Glass

Fully-tempered or laminated glass is commonly used for safety glazing. Tempered glass limits the risk of injury by fracturing into small fragments. Laminated glass limits the risk of injury by retaining the fractured glass on the plastic interlayer and thereby limiting fall-out of glass fragments.

Coated Glass

Coated glass is covered with reflective or low-emissivity (low-E) coatings. In addition to providing aesthetic appeal, the coatings improve the thermal performance of the glass by reflecting visible light and infrared radiation.

Tinted Glass

Tinted glass contains minerals that color the glass uniformly through its thickness and promote absorption of visible light and infrared radiation.

Improving Laminated Glass Durability

Similar to i.g. unit failure, failure of laminated glass by delamination is frequently caused by long-term exposure of the glass edge to moisture. Design recommendations to limit the risk of laminated glass failure include the following:

• Protect the edges of laminated glass from exposure to water to limit the risk of delamination. In general, glazing installation details that promote good waterproofing performance and i.g. unit durability , will also result in improved laminated glass durability.
• Some materials used for laminated glass interlayers, such as polyvinyl-butyral (PVB) are not compatible with many building sealants, so some delamination will occur with butt-glazed joints where the sealant is in contact with the interlayer.
• Some combinations of interlayer products adhere poorly and can cause delamination. This has been the bane of any person who is searching for the cheapest price instead of the best design for the application.

Designing for Fracture Resistance

Design recommendations to limit the risk of glass fracture include the following:

• Avoid glass-to-frame contact. Provide setting blocks and anti-walk pads to separate the glass edge from the metal. Follow GANA glazing guidelines.
• Use heat-strengthened glass for high temperature applications, such as spandrel glass, and where greater resistance to bending an thermal stresses, compared to annealed glass, is required. Limit the residual surface compressive stress to 7,500 psi to reduce the risk of breakage due to Nickel Sulfide (NiS) impurities. Producing heat-strengthened glass within these limits is difficult and requires tight control of the production process to avoid exceeding the upper limit for residual surface compressive stress and introducing the potential for NiS fracture.
• Use fully-tempered (FT) glass where required by code, but avoid use in areas where breakage poses a risk to safety due to the potential for spontaneous breakage from NiS impurities. Where the use of FT glass is unavoidable, and where its breakage poses a threat to people or property, heat-soak the FT glass to reduce the risk of spontaneous breakage due to nickel sulfide inclusions. This additional processing step adds cost and time, but is warranted where the consequences of glass fracture are significant. Alternatively, use laminated glass for safety glazing and fall-out protection. In many applications where FT glass is used, heat-strengthened glass is adequate to meet strength demands and reduces the risk of spontaneous fracture.
• For all glass types avoid edge and surface damage. Such damage concentrates stress from normal wind or thermal loads, especially for tinted glass or spandrel glass enclosing un-vented spaces.

Designing for UV Protection

Ultraviolet radiation can cause material deterioration. Methods to provide UV protection, e.g. for libraries or museums, include providing laminated glazing (the PVB interlayer absorbs UV), certain applied films, or curtains and shades. Depending on the thickness of the PVB interlayer, laminated glass can filter out more than 99% of the UV radiation. Applied films are easily scratched and eventually experience color changes, so they are less durable than laminated glazing.

Logistical and Construction Administration Issues

Inspection and maintenance of exterior glazing sealants requires access to the exterior of windows and curtain walls. Provisions for this access (e.g. suspended scaffolding tie-off anchors) must be made during the design.

Primary and secondary seal continuity and uniformity of minimum width requirements for i.g. units is critical to durability and should be spot-checked on a representative number of actual production units, not just mock-up samples, prior to installation. Mock-up or sample installation often save time and money in the long run as it highlights potential production, lead time, coordination, and performance problems. The production quality of the glazing components and their proper configuration must be checked on a statistically relevant sample of production units.

Glass must be handled carefully during transportation and installation to avoid edge damage and reduce the risk of later glass fracture.

Poor Glazing Design vs Good Design

While we do our best to make sure that the product meets the specifications of the customer, it is always important to have a good DFM review prior to release of the PO.

Here are some commonly found poor design elements and installation features that contrast with the good design features…

• The lack of weep holes in the glazing pocket allows water accumulation and promotes i.g. unit and laminated glass failure.
• Without anti-walk pads, the i.g. unit may “walk” and contact metal frame edges. Glass-to-metal contact may lead to glass edge damage and fracture.
• Fastener penetrations through the glazing pocket allow leakage into the wall cavity below. If sill flashing is present, fasteners set through the glazing pocket will puncture the flashing and cause leakage.
• The flat sill allows water to pond and increases the risk of leakage. Missing sill flashing allows water leakage into the wall cavity.
• Without an integral return edge, the frame provides inadequate bonding substrate for the perimeter sealant. A poorly configured perimeter seal will not be durable and will promote leakage past the window jamb.

Elements of a good glazing design…

The most important features shown in this schematic detail are glazing pocket weep holes, sloped-to-drain sill glazing pocket and sill flashing.

• The glazing pocket weep holes drain water that penetrates the glazing seals. A well-drained glazing pocket prolongs the service life of the insulating glass (by reducing the exposure of edge seals to water), and reduces interior leakage.
• The sill flashing is sloped to the exterior to promote drainage. The window sill frame is attached through the back to a structural clip angle, to avoid fastener penetration of the horizontal portion of the sill flashing.
• The wet glazing seal provides better water penetration resistance than dry glazing (gaskets).
• The anti-walk pad at the window jamb prevents the glass from “walking” in the glazing pocket and contacting the metal frame.
• The perimeter of the window frame includes substantial return legs that provide adequate bonding surfaces for a properly configured sealant joint at the window perimeter.

Emerging Technologies in Glass and Glazing

Self-cleaning or easy-to-clean glass was recently developed and uses titanium dioxide coatings as a catalyst to break up organic deposits. It requires direct sunlight to sustain the chemical reaction and rainwater to wash off the residue. Anorganic deposits are not affected by the coatings.

Photochromic coatings incorporate organic photochromic dyes to produce self-shading glass. Originally developed for sunglasses, these coatings are self-adjusting to ambient light and reduce visible light transmission through the glass. In architectural glass they are typically used to provide shading.

Glass with electrochromic coatings utilizes a small electrical voltage, adjusted with dimmable ballasts, to adjust the shading coefficient and visible light transmission. Like photochromic coatings, they are intended to attain lighting energy savings.

Point-supported glazing is sometimes used in wall systems that are all glass. These systems utilize mechanical anchors at discrete locations near the glass edge, rather than continuous edge supports. Edge-supported glass is typically sized according to glass load resistance charts; such as ASTM E1300. These charts do not apply to point-supported glazing, which requires specific structural engineering analysis.

Relevant Codes, Standards & Info

General Glazing Information

• GANA Glazing Manual, 2004 Edition

Thermal Performance

• AAMA 1503 Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors and Glazed Wall Sections
• AAMA 1504 Voluntary Standard for Thermal Performance of Windows, Doors and Glazed Wall Sections
• AAMA 1505 Voluntary Standards for Thermal Transmittance and Performance

Acoustical Ratings

• AAMA 1801 Voluntary Specification for the Acoustical Rating of Windows, Doors and Glazed Wall Sections

Design Objectives

Functional / Operational—Ensure Appropriate Product/Systems Integration

Products and Systems

See appropriate sections under applicable guide specifications:

• Unified Facility Guide Specifications (UFGS),
• VA Guide Specifications (UFGS),
• DRAFT Federal Guide for Green Construction Specifications,
• MasterSpec®
• Lawrence Berkeley National Laboratory, information on emerging issues and energy efficiency
• Department of Energy, information on emerging issues and energy efficiency
• U.S. Green Building Council, information on the LEED program, news articles related to Green building
• Oikos® Green Building Source, information on sustainable design and Green building, including glazing, windows, skylights, and emerging technology related to sustainable design

Frame Materials

A Wide Range of Fenestration Types

Window manufacturers take a close look at the thermal resistance of the frame when designing new products in an effort to improve the overall efficiency of a window. The frame actually plays an important role of the rating of the window including the U-Factor. While each material has its own unique qualities and benefits, you will discover that when it comes to thermal resistance fiberglass, wood, and vinyl frames outperform metal frames by far. Most composite frames will also perform better than metal frames.

Aluminum or Metal Frames: The advantage of metal frames is that they are strong, light, and virtually maintenance free. The problem is that they also conduct heat very well, meaning they have very little insulating value. In some designs this can be somewhat overcome by inserting a plastic strip between the inside and outside of a split sash.

Fiberglass Frames: One of the benefits of fiberglass is that it has a very low rate of expansion and contraction. Meaning the windows will be dimensionally stable and maintain the tight tolerances for an air-tight fit. In addition, the hollow cavity can be filled with insulation to further enhance the thermal properties of both the frame and sash.

Composite Frames: Composite wood such as laminated lumber or particleboard can be very stable and rot resistant. In general, the windows will have similar thermal values to that of solid wood windows.

Vinyl Frames: The main advantage of vinyl is that it is virtually maintenance free and requires no painting. The newer PVC materials are produced with a UV stabilizer which reduces damage from the sunlight and prolongs the life of the product. Like the fiberglass frames, the cavity in vinyl frames can also be filled with insulation to boost the thermal properties.

Wood Frames: Traditional wood window frames provide good insulation value. The down side with wood is the expansion rate and the routine maintenance required.

As always, we strive to provide the best mix of timing, quality, and performance to our customers. This is called value.